title: Cobalt phosphate-modified barium-doped tantalum nitride nanorod photoanode with 1.5% solar energy conversion efficiency.
abstract: Spurred by the decreased availability of fossil fuels and global warming, the idea of converting solar energy into clean fuels has been widely recognized. Hydrogen produced by photoelectrochemical water splitting using sunlight could provide a carbon dioxide lean fuel as an alternative to fossil fuels. A major challenge in photoelectrochemical water splitting is to develop an efficient photoanode that can stably oxidize water into oxygen. Here we report an efficient and stable photoanode that couples an active barium-doped tantalum nitride nanostructure with a stable cobalt phosphate co-catalyst. The effect of barium doping on the photoelectrochemical activity of the photoanode is investigated. The photoanode yields a maximum solar energy conversion efficiency of 1.5%, which is more than three times higher than that of state-of-the-art single-photon photoanodes. Further, stoichiometric oxygen and hydrogen are stably produced on the photoanode and the counter electrode with Faraday efficiency of almost unity for 100 min.
authors.affiliation: Department of Chemical System Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113 8656, Japan.
authors.forename: Yanbo
authors.initials: Y
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Almudena
authors.initials: A
authors.lastname: Torres-Pardo
authors.forename: Jose M
authors.initials: JM
authors.lastname: González-Calbet
authors.forename: Yanhang
authors.initials: Y
authors.lastname: Ma
authors.forename: Peter
authors.initials: P
authors.lastname: Oleynikov
authors.forename: Osamu
authors.initials: O
authors.lastname: Terasaki
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Asahina
authors.forename: Masahide
authors.initials: M
authors.lastname: Shima
authors.forename: Dongkyu
authors.initials: D
authors.lastname: Cha
authors.forename: Lan
authors.initials: L
authors.lastname: Zhao
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Takanabe
authors.forename: Jun
authors.initials: J
authors.lastname: Kubota
authors.forename: Kazunari
authors.initials: K
authors.lastname: Domen